Meteorology of the Southern Hemisphere

272 Pages·1972·61.894 MB·English

by  Harry van Loon, J. J. Taljaard, T. Sasamori, J. London, D. V. Hoyt, Karin Labitzke, C. W. Newton (auth.), Chester W. Newton (eds.)

METEOROLOGICAL MONOGRAPHS
CO-EDITORS TECHNICAL EDITOR
EUGENE W. BIERLY J. MURRAY MITCHELL, JR. JOHN R. GERHARDT
National Science Foundation Environmental Data Service, NOAA American Meteorological Societ'Y
ASSOCIATE EDITORS
WERNER A. BAUM WILLIAM W. KEu.oGG JEROME SPAR
University of Rhode Island Natl. Center for Atmospheric Research New York University
WALTER HITSCHFELD CHESTER W. NEWTON
McGill University Natl. Center for Atmospheric Research
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rate line, flush with the margin, and should not be under- of the JOURNAL OF THE ATMOSPHERIC SCIENCES,
METEOROLOGICAL MONOGRAPHS
Volume 13 November 1972 Number 35
METEOROLOGY OF THE SOUTHERN
HEMISPHERE
by
Harry van Loon, J. J. Taljaard,
T. Sasamori, J. London, D. V. Hoyt,
Karin Labitzke, C. W. Newton
Edited hy
Chester W. Newton
This collection of papers was initiated, and combined into a monograph, as
a project of the National Center for Atmospheric Research. The National
Center for Atmospheric Research is sponsored by the National Science
Foundation.
PUBLISHED BY THE AMERICAN METEOROLOGICAL SOCIETY
lao 5 8 E A C 0 N ST., 80S T 0 N, MASS. 0 2 I 0 8
AMERICAN METEOROLOGICAL SOCIETY
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Glenn R. Hilst, Chairman
Aeronautical Research Associates of Princeton, Inc.
William H. Hooke
NOAA Research Laboratories, Boukler
Chester W. Newton
National Center for Atmospheric Research
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The Johns Hopkins University
Edward W. Bierly, ex officio,
METEOROLOGICAL MONOGRAPHS
Edward S. Epstein, ex officio
JOURNAL OF APPLIED METEOROLOGY
David M. Ludlum, ex officio
WEATHERWISE
J. Murray Mitchell, Jr., ex officio
METEOROLOGICAL MONOGRAPHS
S. I. Rasool, ex officio
JOURNAL OF THE ATMOSPHERIC SCIENCES
Robert 0. Reid, ex officio
JOURNAL OF PHYSICAL OCEANOGRAPHY
Malcolm Rigby, ex officio
METEOROLOGICAL AND GEOASTROPHYSICAL ABSTRACTS
Kenneth C. Spengler, ex officio
American Meteorological Society
ISBN 978-1-935704-33-1 (eBook)
DOI 10.1007/978-1-935704-33-1
LANCASTER PRESS, INC., LANCASTER, PA.
TABLE OF CONTENTS
PREFACE
-]. MURRAY MITCHELL, JR.
CHAPTER 1 PHYSICAL FEATURES OF THE SOUTHERN HEMISPHERE
-J. J.
TALJAARD
1.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Distribution and topography of the land.... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.3 Pack ice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.4 Sea-surface temperature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
CHAPTER 2 RADIATION BUDGET OF THE SOUTHERN HEMISPHERE
-T. SASAMORI, J. LONDON AND D. v. HOYT
2.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.2 Radiation model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
a. Solar radiation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Cloud-free atmosphere. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Overcast atmosphere........ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Scattering and absorption ratios. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
b. Terrestrial radiation............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.3 Climatological data... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
a. Cloud................................................................... 13
b. Water vapor...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
c. Other climatological parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.4 Results of the calculations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
a. Solar radiation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
b. Terrestrial radiation... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
c. Radiation budget.... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.5 Concluding remarks..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
REFERENCES.................................................................. 22
CHAPTER 3 TEMPERATURE IN THE SOUTHERN HEMISPHERE
-HARRY VAN LOON
3.1 Introduction... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
3.2 Areal distribution of temperature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
a. Summer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
b. Winter...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
c. Comparison with the Northern Hemisphere.... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
3.3 Variation in time. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
a. The yearly cycle at the surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
b. The yearly cycle in the upper air. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
c. The half-yearly cycle in the tropics and subtropics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
d. The second harmonics in middle and high latitudes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
3.4 Latitudinal temperature contrasts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
a. Meridional sections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
b. Variation in time. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
lll
CHAPTER 4 PRESSURE IN THE SOUTHERN HEMISPHERE
-HARRY VAN LOON
4.1 Introduction... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
4.2 Sea-level pressure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
a. Mean and variability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
b. The yearly wave. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
c. The half-yearly wave. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
d. Latitudinal pressure gradients. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
4.3 500-mb height.............................................................. 70
a. Mean and variability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
b. Zonal harmonics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
c. The yearly and halj-yearly waves. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
d. Latitudinal gradients. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
4.4 200-mb height........................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
a. The mean. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
b. The yearly and half-yearly waves. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
c. Latitudinal gradients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
CHAPTER 5 WIND IN THE SOUTHERN HEMISPHERE
-HARRY VAN LooN
5.1 Introduction... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
5.2 Mean and variability of the zonal wind. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
a. Areal mean.......................... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
b. Vertical meridional sections.... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
c. Standard deviations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
5.3 Seasonal variation of the zonal wind. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
a. The yearly wave . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
b. The halj-yearly wave. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
5.4 The meridional wind. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
CHAPTER 6 CLOUDINESS AND PRECIPITATION IN THE
SOUTHERN HEMISPHERE
-HARRY VAN LQON
6.1 Mean cloudiness...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
6.2 Humidity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
a. Dew-point depression............ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
b. Water-vapor content. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
6.3 Precipitation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
a. Annual precipitation and evaporation over the oceans . . . . . . . . . . . . . . . . . . . . . . . . . . . 1O S
b. Frequency and amount in the extreme seasons. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
c. Halj-yearly waves in the precipitation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
d. Antarctica............................................................... 110
e. Precipitation and the cloud band in the Pacific Ocean. . . . . . . . . . . . . . . . . . . . . . . . . . . 111
iv
CHAPTER 7 THE STRATOSPHERE IN THE SOUTHERN HEMISPHERE
-KARIN LABITZKE AND HARRY VAN LOON
7.1 Introduction... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
7.2 Mean circulation in the lower stratosphere....... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
a. Summer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
b. Autumn................................................................. 116
c. Zonal wave I. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
d. Winter............ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
e. Midwinter warmings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
f. Final warmings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
7.3 Periodic and unperiodic oscillations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
a. The quasi-biennial oscillation.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
b. The yearly and half-yearly waves in the temperature. . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
7.4 Geostrophic wind in 1969. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
APPENDIX
Annual March of SIRS Radiances. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
CHAPTER 8 SYNOPTIC METEOROLOGY OF THE SOUTHERN HEMISPHERE
-J. J.
TALJAARD
8.1 Introduction... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
8.2 Historical survey. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
8.3 Observation networks and analysis........ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
a. Observation networks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
b. Analysis procedures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
c. Reliability of the IGY maps................................................ 144
d. Analysis using satellite data..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
8.4 Air masses................ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
a. Survey of literature............ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
b. Air-mass classification and source regions.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
8.5 Fronts....... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
a. Frontal analysis in the Southern Hemisphere. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
b. Climatic fronts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
c. Frontal phenomena in the subtropics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
d. Fronts over Antarctica. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
8.6 Anticyclones. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
a. Early ideas. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
b. Advances since World War II.............................................. 160
c. Distribution of anticyclones... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
d. Meridional profiles.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
e. Movement of anticyclones............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
f. Variations in movement of anticyclones... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
g. The antarctic anticyclone. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
h. Comparison of anticyclones in the Northern and Southern Hemispheres.. . . . . . . . . . . 168
8. 7 Cyclogenesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
a. Survey of pre-IGY studies.................................................. 169
b. Cyclogenesis during the IGY................................................ 170
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8.8 Cyclones .................................................................. . 172
a. Early views . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 72
b. Advances since World War II.............................................. 172
c. Distribution of cyclones. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
d. Meridional profiles of cyclone frequency. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
e. Movement of cyclones. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
f. Variations in the distribution and movement of cyclones. . . . . . . . . . . . . . . . . . . . . . . . . 180
g. Speed of cyclones. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
h. Comparison of cyclone frequencies in the Northern and Southern Hemispheres. . . . . . 181
8.9 Zonal and meridional circulation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182
a. Fluctuations of the circulation intensity.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182
b. Blocking anticyclones and cut-off cyclones. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
c. Meridional displacements of cold and warm air... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188
8.10 Relationships between some phenomena..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189
a. The cloud bands of the South Pacific and Atlantic Oceans. . . . . . . . . . . . . . . . . . . . . . . 189
b. The circulation of Australia and the Western Pacific in winter. . . . . . . . . . . . . . . . . . . 192
8.11 Tropical weather systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
a. General remarks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
b. The intertropical convergence zone. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
c. Tropical southern Africa. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
d. The tropical Indian Ocean. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
e. Indonesia and northern Australia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
f. The South Pacific Ocean. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206
g. Southern tropics of South America........................................... 209
h. The tropical South Atlantic................................................. 211
CHAPTER 9 SOUTHERN HEMISPHERE GENERAL CIRCULATION IN RELATION
TO GLOBAL ENERGY AND MOMENTUM BALANCE REQUIREMENTS
-C. W. NEWTON
9.1 Introduction... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
9.2 Angular momentum generation and transfer... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
a. Overall features in summer and winter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
b. Seasonal balance, broad-scale features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216
c. Summary of torques and momentum flux. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220
d. Seasonal variations of 500-mb flux.............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221
e. Transfer by moving and standing waves. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222
9.3 Eddy transfer, maintenance of zonal winds, and toroidal circulations. . . . . . . . . . . . . . 222
a. Momentum accumulation and kinetic energy balance... . . . . . . . . . . . . . . . . . . . . . . . . . 222
b. Momentum transfer in relation to zonal wind..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223
c. Hadley and Ferrel cells. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224
d. Zonal winds in relation to Hadley circulations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228
9.4 Water balance... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228
a. Annual precipitation, evaporation, and meridional vapor flux. . . . . . . . . . . . . . . . . . . . 229
b. Seasonal water balance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230
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9.5 Energy balance......................................... . . . . . . . . . . . . . . . . . . . . 232
a. Heat balance of earth-atmosphere system. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232
b. Apportionment of meridional heat flux between oceans and atmosphere. . . . . . . . . . . . . 233
c. Eddy and toroidal heat fluxes in the atmosphere. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235
d. Seasonal energy fluxes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237
e. Summary of energy balance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240
APPENDIX A
Seasonal Torques and Angular Momentum Fluxes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243
APPENDIX B
Mechanisms of Oceanic Heat Flux . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244
APPENDIX C
Components of Annual Energy Balance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246
REFERENCES.................................................................... 247
SUBJECT INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259
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PREFACE
Until about fifteen years ago the history of progress oceanic) mass exchange processes will suffice to cir
in both the theory and practice of meteorological cumscribe the problem.
science had been one of relative neglect of the Southern For these and other reasons it is most timely that
Hemisphere. An obvious reason for this neglect was a comprehensive and eminently authoritative treatise
the almost total lack of regular synoptic observations on meteorology of the Southern Hemisphere should
from vast reaches of the southern oceans, as required make its appearance, with the publication of this
for a satisfactory understanding of events and the Meteorological Monograph. The idea of preparing
comprehensive description of climate in the Southern this monograph was conceived during the preparation
Hemisphere. A second reason was that atmospheric of an historical map series for the Southern Hemi
theorists who were mostly preoccupied with the better sphere, in Pretoria. It received further impetus when
documented meteorology of the Northern Hemisphere the World Meteorological Organization assigned to
saw little need to cast their eyes southward much the South African Weather Bureau the task of analyz
beyond the equator. As early as 1735 and the pioneer ing and publishing the IGY maps for that hemisphere.
ing foray of George Hadley into the theory of the The National Center for Atmospheric Research
global atmospheric circulation, it had been postulated (NCAR) then became involved, where a group of
that the global circulation was adequately character interested scientists volunteered the facilities necessary
ized as two circulations, one on either side of the equa to undertake a comprehensive analysis of surface and
tor and effectively buffered one from the other by a upper-air climatology for the project. The collabora
comparatively imperturbable "equatorial belt of calms tion of the NOAA Environmental Data Service,
and rains." It therefore seemed a reasonable hope on through its National Climatic Center in Asheville,
the part of northern theorists that the behavior of the North Carolina, greatly assisted in the endeavor by
atmosphere in their hemisphere could be successfully making available a quantity of unpublished upper-air
understood-and predicted-without their having to data in their possession.
inquire into the state of affairs in the Southern The foundation for this monograph is the four
Hemisphere. volume atlas, Climate of the Upper Air: Southern
Since 1958, several important developments have Hemisphere (Taljaard et al., 1969; van Loon et al.,
been responsible, each in its own way, for a rapid 1971; Jenne et al., 1971; Crutcher et al., 1971). This
escalation of interest in the meteorology of the atlas contains maps, cross sections, and tables that
Southern Hemisphere. First among these develop present the mean hemispheric fields of the various
ments was the global-scale data gathering effort of the meteorological parameters in far greater detail than
International Geophysical Year, which filled large it was possible to reproduce here.
voids in our knowledge of atmospheric behavior in Preparation of each volume of the atlas was a joint
both equatorial and southern latitudes. Second was effort of H. van Loon (NCAR), R. L. Jenne (NCAR),
the advent of the meteorological satellite, which for J. J. Taljaard (South African Weather Bureau), and
the first time gives us the capability of mapping atmo H. L. Crutcher (NOAA). On behalf of the authors of
spheric conditions from pole to pole on a day-by-day this monograph, I call especial attention to the monu
basis, and which has uncovered clear evidence of mental groundwork done by Mr. Jenne for the atlas
important energy transactions between the air circu project. By his careful collection and processing of the
lations of the two hemispheres. Third has been the original observational data, and by his meticulous
development of increasingly realistic numerical models checking of the spatial and temporal continuity of the
of the global atmospheric circulation and climate, and hand analyses derived in the project, Mr. Jenne has
experiments using such models which tend to confirm made an indirect but important contribution to the
the importance of interhemispheric energy and mo quality of this monograph. In drawing comparisons
mentum exchange processes to the evolution of with the Northern Hemisphere, the recent series of
weather and climate in the higher latitudes of both climatological atlases for that hemisphere prepared by
Hemispheres. Fourth has been a growing awareness of Dr. Crutcher and his collaborators has been of special
those concerned with environmental quality that value. Professor J. T. Houghton and collaborators
certain waste discharges from human activities (for (Oxford University) and Drs. S. Fritz and S. D.
example, DDT and carbon dioxide) become so widely Soules (NOAA) generously made available the satel
dispersed into the atmosphere and oceans that nothing lite radiometer measurements used extensively in
iess than a pole to pole view of atmospheric (and Chapter 7.
ix